JEE Main · 2021 · 26 Feb 2021 · Shift 2 · Semiconductors

If the highest frequency modulating a carrier is 5 kHz , then the number of AM broadcast stations accommodated in a 90 kHz bandwidth are ____

Answer: 9

Solution

Amplitude modulation places sidebands on both sides of the carrier, so one station occupies a band of

2 f_{m}

. With

f_{m} = 5

kHz each station needs

2 \times 5 = 10 kHz

A band of

90

kHz therefore holds

\frac{90}{10} = 9

stations.

JEE Main · 2021 · 26 Feb 2021 · Shift 2 · Integer answer